JP2008091764A - Electronic component, and film capacitor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To form an electrode having a sufficient thickness, without giving any thermal influence to a film material (a base material). <P>SOLUTION: In the forming method of an electronic component, one or more kinds of pure Cu, a Cu-based alloy, pure Al, and an Al-based alloy are selected as a thermal-spray material for the electronic component, and then, the supersonic flow of a gas having a temperature not higher than the melting point or softening temperature of the thermal-spray material is generated, the powder particles of the thermal-spray material are injected into the supersonic-flow gas, and the thermal-spray material is made to collide with the base material in the state of its solid phase so as to use the resultantly generated film as the electrode of the electronic component. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an electronic component and a film capacitor.

  In recent years, along with technological advancement in the field of information communication, there is a strong demand for downsizing, weight reduction, and high performance of electronic components constituting control equipment. Film capacitors are no exception, and efforts are being made to make dielectric films even thinner. For example, a method for forming a capacitor by forming a metal thin film electrode at the same time while forming a thin film of a dielectric having a thickness of 1 μm or less by a vacuum vapor deposition method will be required for a method of manufacturing a film as a dielectric in advance.

  Patent Document 1 below discloses that a film capacitor formed by laminating an organic material thin film dielectric is formed by thermally spraying brass on an electrode end surface to form an end surface electrode. However, forming the electrode by thermal spraying has a fatal defect that the film itself is melted or thermally deformed due to the thermal effect of thermal spraying.

  That is, since the film is made of a resin material, melting and thermal deformation due to the thermal effect of thermal spraying are likely to be a problem (Problem 1), and since thermal spraying is a process of spraying while melting the powder material in the atmosphere, Thermal spray coating has the characteristic of being easily oxidized. For this reason, there is a problem that the electrical resistance tends to be high and the electrical loss is large when used as an electrode or the like (Problem 2).

  On the other hand, there is a thermal spray technique called “cold spray”. In cold spray, a gas having a temperature lower than the melting point or softening temperature of the thermal spray material is converted into a supersonic flow, and the particles of the thermal spray material are injected into the supersonic flow gas, and collide with the base material in a solid state. This is a technique for forming a film. Compared to the conventional plasma spraying method, flame spraying method, and high-speed flame spraying method, the temperature of the working gas for heating and accelerating the sprayed material particles is significantly lower. The substrate is allowed to collide with the substrate at a high speed, and the energy and energy cause plastic deformation of the substrate and particles to form a film. The film thus obtained has excellent properties such as denseness, high density, high heat and electrical conductivity, little oxidation and thermal deterioration, and good adhesion.

  Patent Document 2 listed below discloses an invention in which an insoluble electrode used for electroplating is formed by cold spraying. Specifically, Ti, Ti alloy, Ta, Ta alloy, Nb, Nb alloy, on the surface of the base material made of any of Ti, Ti alloy, Ta, Ta alloy, Nb, Nb alloy, Zr, Zr alloy, A Zr, Zr alloy, and an oxide of the metal or the alloy, and an intermediate layer in which the amount of the oxide is 0.01 to 2% by volume, and a platinum group on the surface of the intermediate layer An insoluble electrode having an outermost layer made of a metal oxide.

  In the invention described in Patent Document 2, the insoluble electrode used for electroplating is formed by cold spraying, but the thermal spray material is limited to Ti, Ti alloy, Ta, Ta alloy, Nb, Nb alloy, Zr, Zr alloy. ing. As a result, the following problems have arisen.

  Since Ti-based, Ta-based, Nb-based, and Zr-based materials having a relatively high electrical resistivity are selected as the materials used, the fabricated electrodes also have a high electrical resistivity and electrical loss tends to increase (problem 3). ). Since a relatively hard Ti-based, Ta-based, Nb-based, or Zr-based material is selected as the material used, the cold spray coating is difficult to flatten the particles. As a result, it is difficult to form a sensitive film, the electrical resistivity tends to be high, and the film formation time is long because it is difficult to form a film (Problem 4). Relatively expensive Ti-based, Ta-based, Nb-based, and Zr-based materials are selected as the materials used (Problem 5). Since the electrode thickness is small, the heat capacity is small, the temperature rises due to Joule heat, and the substrate is affected by heat (Problem 6).

  Furthermore, in Patent Document 3 below, as a method for forming an electrode in a sodium-sulfur battery, a high resistance layer material is integrally formed and mounted on the surface of the collector electrode in a porous state. Is not limited to thermal spraying, but there is a description that it is performed by a cold spray method, a coating method, a sintering method, or the like. In addition, there is a description that the material of the collector electrode is carbon, graphite, chromium, molybdenum or the like, or a chromium-cobalt alloy, chromium-iron alloy, or the like.

  The invention described in Patent Document 2 has the following problems. Since a Cr-based or Mo-based material having a relatively high electrical resistivity is selected as the material to be used, the manufactured electrode also has a high electrical resistivity, which tends to increase electrical loss (Problem 7). Since a relatively hard Cr-based or Mo-based material is selected as the material to be used, the cold spray coating is difficult to flatten the particles. As a result, it is difficult to form a dense film, the electric resistivity tends to be high, and the film formation time is long because it is difficult to form a film (Problem 8). A relatively expensive Cr-based or Mo-based material is selected as the material used (Problem 9).

JP 2000-124061 A JP 2004-307969 A JP 2005-197139 A

  An object of the present invention is to solve various problems of the prior art and form an electrode having a sufficient thickness without affecting the film material (base material).

  The present inventor has found that the above-mentioned problems can be solved by selecting as a spray material for a specific cold spray and forming an electrode on a specific resin substrate, and has reached the present invention.

  That is, first, the present invention is an invention of an electronic component in which an electrode is formed, and the electrode uses one or more selected from pure Cu, Cu-based alloy, pure Al, and Al-based alloy as a thermal spray material. , A gas having a temperature equal to or lower than the melting point or softening temperature of the thermal spray material is made to be a supersonic flow, and powder particles of the thermal spray material are put into the supersonic flow gas, and the thermal spray material is left in a solid state on the substrate. It consists of a film produced by collision. Here, the thermal spraying method includes what is called a cold spray. However, in the present invention, not only the narrow spray spray but also a derivative technique derived from a cold spray having a slight width in temperature and the like is applied. A cold spray in a broad sense including these is referred to as “cold spray” in the present invention.

  If the electrode is formed using the above method, it is easy to reduce the electrical resistivity of the electrode as compared with the conventional thermal spraying, which is advantageous in suppressing electrical loss and improving the sensitivity of the sensor.

  By limiting the thermal spray material to at least one selected from pure Cu, Cu-based alloy, pure Al, and Al-based alloy, it is possible to form an electrode with extremely low electrical resistance as compared with conventionally known thermal spray materials. It becomes possible.

  The electronic component of the present invention is not particularly limited, and includes various electronic components having electrodes formed by metal spraying. Specifically, film capacitors, wiring boards, thermistors (temperature sensors), batteries, fluorescent lamps, image display devices, varistors, piezoelectric elements, thermoelectric elements, infrared radiation devices, ultraviolet radiation devices, discharge electrodes, etc. are preferably exemplified. . Among these, the film capacitor is particularly preferable as an electronic component to which the present invention is applied because it can take advantage of the cold spray low temperature process.

  Secondly, the present invention is an invention of a film capacitor, wherein a gas having a temperature equal to or lower than a melting point or a softening temperature of a thermal spray material made of a metal material is converted to a supersonic flow, and the powder of the thermal spray material is put into the supersonic flow gas. The film capacitor is characterized in that a film formed by introducing grains and causing the sprayed material to collide with a base material made of a resin material in a solid state is used as an electrode.

  In the film capacitor of the present invention, the thermal spray material is not particularly limited, but at least one selected from pure Cu, Cu-based alloy, pure Al, and Al-based alloy is particularly preferable.

  Although it is necessary to form an electrode on a resin material for a film capacitor, since the temperature can be sprayed by suppressing the temperature rise of the substrate by the cold spray, the thickness of the electrode can be 0.2 mm or more.

An electronic component in which an electrode is formed by cold spraying using one or more selected from pure Cu, Cu-based alloy, pure Al, and Al-based alloy as a thermal spray material,
(1) Problems 3 and 7 are solved because a material having a higher electrical conductivity than Ti, Ta, Nb, Zr, Cr, and Mo is selected.
(2) Problems 4 and 8 are solved because a softer material is selected as compared to Ti, Ta, Nb, Z, Cr, and Mo.
(3) Since it is a low-cost material as compared with Ti, Ta, Nb, Zr, Cr, and Mo, problems 5 and 9 are solved.

A film capacitor in which electrodes are formed on a base material made of a resin material by cold spray
(4) Since the cold spray is a process in which the powder material is sprayed without melting, the thermal effect on the substrate is smaller than that of thermal spraying. Therefore, Problem 1 is solved.
(5) Problem 2 is solved because it is less susceptible to oxidation than conventional thermal spraying.

By setting the thickness of the electrode of the film capacitor to 0.2 mm or more,
(6) The heat capacity of the electrode is improved and the problem 6 is solved.

Examples of the present invention and comparative examples are shown below.
[Example 1]
Thermal spraying of pure Cu, pure Al, pure Ti, pure Ta, pure Nb, pure Zr, pure Cr, and pure Mo is performed on the circular shape of both bottom surfaces of a cylindrical resin substrate having a diameter of 25 mm and a height of 40 mm. Cold spray was used as a material to determine the electrical resistivity.

[Comparative Example 1]
Conventional thermal spraying was performed by using pure Cu and pure Al as the thermal spraying material for 1-2 mm on the circular shape of both bottom surfaces of a cylindrical resin substrate having a diameter of 25 mm and a height of 40 mm, and the electrical resistivity was obtained.

  FIG. 1 shows electrical resistivity when cold spraying is performed using pure Cu, pure Al, pure Ti, pure Ta, pure Nb, pure Zr, pure Cr, and pure Mo as the thermal spray material. At the same time, the electrical resistivity of these metal bulk materials is shown. Furthermore, FIG. 2 shows the electrical resistivity when cold spraying is performed using pure Cu and pure Al as thermal spray materials, the electrical resistivity when performing conventional thermal spraying using these metals as thermal spray materials, and bulk materials of these metals. The electrical resistivity is shown.

  From the results of FIG. 1 and FIG. 2, the cold spray film using pure Cu and pure Al as the thermal spray material has an extremely low electrical resistivity compared to the cold spray film using the other six types of metal as the thermal spray material. I understand. This is because (1) pure Cu and pure Al have low electrical resistivity of the bulk material itself, and (2) pure Cu and pure Al are soft metals, so a dense film is likely to be generated. .

  In addition, from the results of FIG. 2, the cold spray coating has a lower electrical resistivity than the conventional thermal spray coating. This is because conventional thermal spraying is a process in which the powder material is sprayed while being melted in the air, and the thermal spray coating is likely to oxidize, and thus the electrical resistivity tends to be high, whereas cold spray does not melt the powder, This is because the thermal spray coating is difficult to oxidize and the electrical resistivity does not increase.

  For reference, Table 1 shows the electrical resistivity data (μΩ · cm) and Table 2 shows the Vigars hardness (HV).

[Example 2]
Cold spray using pure Cu as a thermal spray material was performed on 1 to 2 mm on the circular shape of both bottom surfaces of a cylindrical resin substrate having a diameter of 25 mm and a height of 40 mm, and the change in the substrate temperature with respect to the film thickness was determined.

[Comparative Example 2]
Conventional thermal spraying was performed using pure Cu as the thermal spray material on the circular shape of both bottom surfaces of a cylindrical resin substrate having a diameter of 25 mm and a height of 40 mm, and the change in the substrate temperature with respect to the film thickness was determined. .

  FIG. 3 shows the results of Example 2 and Comparative Example 2 with respect to the film thickness when the cold spray is performed using pure Cu as the spraying material (■) and when the conventional spraying is performed (●). It shows as a graph which shows the change of temperature.

  From the results shown in FIG. 3, when cold spraying is performed using pure Cu as a thermal spray material, a target temperature of 100 ° C. or less is possible considering the heat resistance of the resin substrate. However, when conventional thermal spraying is performed, film formation is performed. It can be seen that the target temperature exceeds 100 ° C. from an early stage.

[Example 3]
Cold spraying is performed using pure Cu as a thermal spray material on the circular shape of both bottom surfaces of a cylindrical resin substrate having a diameter of 25 mm and a height of 40 mm. I sought change.

  In FIG. 4, the result of Example 3 is shown as a graph. From the results of FIG. 4, when the electrode thickness is 0.2 mm or more, the target temperature of 100 ° C. or less is possible considering the heat resistance of the resin substrate, but when the electrode thickness is less than 0.2 mm, the heat resistance of the resin substrate is considered. It can be seen that the target temperature exceeds 100 ° C. From this, it can be seen that a film capacitor using a resin substrate preferably has an electrode thickness of 0.2 mm or more.

  By forming an electrode using cold spray, the electrical resistivity of the electrodes of various electronic components is low, and thermal damage of the target substrate can be suppressed low.

The electrical resistivity when performing cold spraying using pure Cu, pure Al, pure Ti, pure Ta, pure Nb, pure Zr, pure Cr, and pure Mo as the thermal spray material is shown. At the same time, the electrical resistivity of these metal bulk materials is shown. The electrical resistivity when performing cold spraying using pure Cu and pure Al as thermal spray materials, the electrical resistivity when performing conventional thermal spraying using these metals as thermal spray materials, and the electrical resistivity of bulk materials of these metals are shown. . The graph which shows the change of the base-material temperature with respect to the film-forming film thickness at the time of performing a cold spray using pure Cu as a thermal spray material, and performing the conventional thermal spraying. The graph which shows the change of the electrode surface temperature with respect to the film-forming electrode thickness at the time of an actual machine operation | movement, performing a cold spray by using pure Cu as a thermal spraying material with respect to a resin substrate.

Claims (5)

  One or more selected from pure Cu, Cu-based alloy, pure Al, and Al-based alloy is used as a thermal spray material, and a gas having a temperature lower than the melting point or softening temperature of the thermal spray material is converted into a supersonic flow, and the supersonic flow gas An electronic component comprising: a coating formed by injecting powder particles of the thermal spray material therein and colliding the thermal spray material with a base material in a solid state.   The electronic component according to claim 1, wherein the base material is a resin material.   A gas having a temperature equal to or lower than the melting point or softening temperature of a thermal spray material made of a metal material is made into a supersonic flow, and powder particles of the thermal spray material are put into the supersonic flow gas, and the thermal spray material is in a solid state while being in a solid state. A film capacitor characterized in that an electrode is a film formed by colliding with a base material made of a material.   4. The film capacitor according to claim 3, wherein the thermal spray material is one or more selected from pure Cu, Cu-based alloy, pure Al, and Al-based alloy.   The film capacitor according to claim 3 or 4, wherein the electrode has a thickness of 0.2 mm or more.

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